Vacuum-tube rectifier



H. HI STRONG ,June 17, 1930.

VACUUM TUBE} RECTIFIER Filed Nov. 927 4 Sheets-Sheet l H arz'y H Strong Inventor By Attorneys June 17 1930. STRONG 1,764,283

VACUUM TUBE RECTIFIER Filed ilov. l, 1927 4 Sheets-Sheet 2 "K 0000000001363500000000000 000000000009000000000000 :9, uooooooomooooooooooouon oooooooowOoooooooooouou v eonooooooooooooo00000000 s oonooooooooooooooooooouo k uonooooooOQooooooooounoo m IL aoooooooooooooooooaooooo w H arz'yh'. Strong Inventor Attorneys June 17, 1930. H H. STRONG VACUUM TUBE RECTIFIER Filed Nov. 1, 1927 4 Sheets-Sheet 5 mm S Q H arr-3 H Sire 7723 I nve W/ Attorneys June 17, 1930. H. H. STRONG I VACUUM TUBE RECTIFIER Filed Nov. 1927 4 Sheets-Sheet 4 HarryHStrong Inventor BE/M Attorneys Patented June 17,- 1930 UNITED STATES PATENT ormer.

HARRY H. STRONG, OI TOLEDO, OHIO, ASSIGNOB, TO THE STRONG ELECTRIC CORPO- BATION, OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE VACUUM-TUBE nnc'rrrma Application filed November 1, 1927. Serial No. 230,255.

My invention relates to vacuum tube rectifiers, particularly to vacuum tube rectifiers for use with motion picture projector arc lamps, and the principal object of my invention is to provide a new and improved rectifier of this type. In the drawings accompanyin this specification and forming a part 0 this application I have shown, for purposes of illustration, one form which my inventionmay assume, and in these drawigure 1 is a front elevation of the em bodiment of my invention herein shown,

Figure 2 is a rear elevation of this embodiment of my invention,

Figure 3 is a side elevation,

Figure 4 is a top plan view,

Figure 5 is a view similar to Figure 4 but with the apertured shield removed,

Figure 6 is a view of the inner face of the front side plate showing the transformer and tubes dotted to indicate their correlation to the front side plate, while Figure 7 is a dia rammatic view showing 2 the connections of t e rectifier to the power and are lamp circuits.

The embodiment of my invention herein shown comprises front and rear side plates 11 and 12 provided at their edges with flanges 13 and 14 abutting the legs 15 of an H-type core 16 formed of laminations 17 extending parallel to the side plates 11 and 12, having the ends of the legs 15 connected by cross legs 18, and having the centers of the legs 15 connected by a cross bar 19 which is provided intermediate the legs 15 with an air gap 20, carries at one side of the ap 20 the primary and secondary of a trans ormer 21 herein combined as an autotransformer coil 22, and carriesat the other side of the air gap 20 two secondary coils 23.

Connectingthe two side plates 11 and 12 are three upper tiebolts 24 and three lower tiebolts 25 to ether effective to hold the side lates 11 an 12 assembled with the transformer 21, acting through the flanges '13 and 14 to compact the laminations 17 of the core- 16, and serving also to support the transformer 21 from the side plates 11 and 50 12 by engagement of the lower tiebolts 25 with the lower face of the transformer core 16 and of the upper tiebolts 24 with the upper face of a vacuum tube socket baseplate 26 overlying the upper face of the transformer core 16 and carrying mounted thereon in any suitable manner two sockets 27 each adapted to receive a vacuum tube 28 of the type having two base contacts connected to the two ends of the filament and cooperating respectively with the shell and center contact of the socket, and a ti contact 29 connected to the tube plate ans herein engaged by a cross conducting stri 30 common to the two tubes 28 and secure in position by means of thumb screws 31 on aging the tube tip contacts 29.

[he side plates 11 and 12 are provided with suitable feet 32 for supportin the entire rectifier, with inwardly exten ing projections 33 extending proximate the coils 22 and 23' of the transformer 21 to additionall steady the transformer 21 within the en plates 11 and 12, and with upwardly extending projections 34 and 35 outlining a chamber 43 for the vacuum tubes 28 completed by an apertured metal shield 36 extendin for the greater part of its length about fips 37 formed along the peripheries of the side plate extensions 34 and 35, ex-

' tending at its ends within lips 38 formed by the 11 per edges of the flanges 13 and 14 of the side plates 11 and 12, and held in positionassembled upon the side lates 11 and 12 enclosing the vacuum tube 0 amber 43 by means of machine screws 39 extending through the apertured shield 36 into the li s 37 of the extensions 34 and 35 of the si e plates 11, and 12.

Formed in the rear side plate 12 are four apertures 40 for the passage of four conductors, a line conductor 41 connected at 42 to one end of the autotransformer coil 22, a second line conductor 44 connected to the switch arm 46 of a compensating switch 47 provided with eight contacts 48 connected y means of conductors 49 at points 50 to the end of the autotransformer coil 22 remote from that end of the coil 22 to which is connected the line conductor 41, an arc lamp conductor 51 connected directly to the cross conductors 30 connecting the tip contacts 29 of the tubes 28, and a second arc lamp conductor 52 connected to an intermediate or neutral point 53 on the autotransformer coil 22. Connected to the point 42 of the autotransformer coil 22, and to a point 54 spaced an equal distance along the coil 22 from the neutral point 53 but in the opposite direction, are a pair of conductors 55 and 56 connected at their free ends at 62 and 57 to the inner ends of the secondary coils 23, while leading from the outer ends of the secondary coils 23 are pairs of conductors 58 and 59 connected to the secondary coils 23 at points 60 and 61 disposed respectively at the ends of the coils 23 and a few turns within the ends of the coils 23, and each pair of conductors 58 and 59 is connected to the shell and center contact of one of the tube sockets 27, and therefore to the two ends of the filaments of one of the tubes 28.

From the above description it will be understood by those skilled in the art that the embodiment of my invention herein shown and described provides a rectifier wherein the main voltage transformation is accomplished by means of the less expensive autotransformer, wherein suflicient voltage transformation is accomplished by means of secondaries disposed on the opposite side of the core air gap to provide the dropping voltage desirable in arc lamp operation upon increase in current, or perhaps rather the rise in voltage desirable in arc lamp operation upon decrease in current, and wherein the energization of the lamp filaments is effected from the same coils forming the secondaries of the transformer. In the particular embodiment of my invention herein shown I form the autotransformerwith a total of one hundred and forty-two turns, seven groups of six turns between the conductors 49 leading to the compensating switch 47, and one hundred turns in the balanceof the coil divided into thirty-five turns between the neutral 53 and each of the points 42 and 54 to which the secondaries 23 are connected, and thirty turns between the point 54 and the first compensating switch conductor point 50; in this embodiment of my invention I form each of the secondar coils 23 with sixty turns, and I position eacli of' the conductors 59 receiving points 61 four and one-half turns from the end of the corresponding secondary coil 23. Under these circumstances, and with a core of suitable dimensions, and with one hundred and ten voItsIaipplied to the input side of therectifier, nd that with the compensating switch 47 on the outer end contact point 48 the voltage of the lamp circuit between the conductors 51 and 52 will be approximately 45 volts attwelve amperes and will rise to some seventy volts at no load, and that with the compensating switch 47 set on the inner end contact 48 the voltage between the arc lamp conductors 51 and 52 will rise from approximately fifty-five volts at twenty-two amperes to approximately ninety volts at no oad It of course will be understood by those skilled in the art that intermediate adjustments of the compensating switch 47 will yield intermediate voltages, and that other results may be obtained by constructing my rectifier of other dimensions and proportions, and that the rectifier will be constructed of other dimensions and proportions for other uses. At the same time it also will be understood by those skilled in the art that these and other changes may be made, and that the particular embodiment of my invention herein shown and described may be variously changed and modified, all without departing from the spirit of my invention or sacrificing the advantages of my invention, either those advantages hereinabove specifically pointed out, or the pleasing and sturdy construction herein disclosed, or those other advantages not specifically pointed out or suggested herein but nevertheless apparent to those skilled in the art.

It therefore will be understood that the disclosure herein is illustrative only, and that my invention is not limited thereto.

I claim l. A vacuum tube rectifier comprising: a transformer having portions of its core projecting beyond its coil means on the two ends of said coil means; a pair of side plates flanking said transformer, provided on their edges with flanges extendmg substantially to the sides of said projecting portions of said cord, and extending above said transformer to outline a vacuum tube chamber; and an apertured metal shield extending between said side plates to enclose said chamber.

2. Avacuum tube rectifier comprising: a transformer having portions of its core pro- -jecting beyond its coil means on the two ends of said coil means; a pair of side plates flanking said transformer, provided on their edges with flanges extending substantially to the sides of said rojecting portions of said core, and exten ing substantially unflanged above said transformer to outline a vacuum tube chamber; and an apertured metal shield extending between said side plates to enclose said chamber.

3. A vacuum tube rectifier comprising: a transformer having portions of its core projecting beyond its coil means on the two ends of said coil means; a pair of side plates flanking said transformer, rovided on their edges with flanges extending substantially to the sides of said projectin portions of said core, extending above sai transformer to outline a vacuum tube chamber, and provided on said extensions with inwardly projectin lips; and an apertured metal shield exten ing between said side plates around said lips terminating under said flanges and to enclose said chamber.

4. A vacuum tube rectifier comprising: a transformer having portions of its core projecting beyond its coil means on the two ends of said coil means; a pair of side plates flanking said transformer, provided on their edges with flanges extending substantially to the sides of said-projecting portions of said core, and extending above said transformer to outline a vacuum tube chamber; an apertured metal "shield extending between said side plates to enclose said chamber; and a compensating switch carried by the extension of one of said end plates.

5. A vacuum tube rectifier comprising: a transformer having portions of its core projecting beyond its coil means on the two ends of said coil means; a pair of side plates flanking said transformer, provided with lugs to engage said coil, and provided on their edges with projections abutting the sides of said projecting portions of said core; and means securing said sideplates so assembled with said core and serving also to support said transformer from said side plates. I

6. A vacuum tube rectifier comprising: a

transformer having portions of its core pro-- jecting beyond its coil means on the two ends of said coil means; a pair of side plates flanking said transformer and provided on their edges with projections abutting the sides of said projecting portions of said core; a tube socket base plate resting on the top of said core; and means'securing said siyle plates so assembled with said core and serving also to support said transformer from said side plates and to secure said base plate in position.

7. A vacuum tube rectifier comprising: a transformer having port-ions of its core projecting beyond its coil means on the two ends of said coil means; a pair of side plates flanking said transformer and provided on their edges with projections abutting the sides of said pro ecting portions of said core; a tube socket base plate resting on the to of said core {and tiebolts securing said Sit e plates so assembled with said core and serving also to support said transformer from said side plates and to secure said base plate in position.

8. A vacuum tube rectifier comprising: a transformer having a laminated core, and having portions of said core projecting beyond its coil means on the two ends of said coil means; a pair of side plates flanking said transformer and provided on their edges with projections'abutting the sides of said projecting portions of said core; the

laminations of said core being parallel to 9. A vacuum tube rectifier comprising: a

core provided with a gap; a primary disposed on one side of said ga a secondary disposed on the same side 0 said gap and provided with a neutral lead and with two end leads; and a pair of'secondary coils disposed on the other side of said gap and connected one to one of said end leads and the other tothe other of said end leads.

10. A vacuum tube rectifier comprising: a core provided with a gap; an autotransformer disposed on one side of said gap and provided on its secondary .side with a neutral lead and with two end leads; and a pair of secondary coils disposed on the other side of said gap and connected one to one of said end leads and the other to the other of said end leads.

11. A vacuum tube rectifier comprising: a

core provided with a gap; a primary disposed on one side of said ga a secondary disposed on the same side 0 said gap and provided with a neutral lead and with two end leads; a pair of secondary coils disposed on the other side of said gap and connected one to one of said end leads and the other to the other of said end leads; and a pair of tubes having their filaments connected across the end turns of said sec ondary coils. Y

12. A vacuum tube rectifier comprising: a pair of tubes each having a plate element and a filament element; primary windings; main, secondary windings provided with a neutral terminal intermediately thereof; end-turn secondary windings spaced from said primary and main secondary windings and having their inner terminals connected to the ends of said main secondary windings and their outer terminals connected one to one of said elements of one of said tubes and the'other to one of said elements of the other of said tubes; and a core for said windings formed to effect at higher magnet c densities a magnetic leak by-passing sa1d.

end-turn secondary windings.

rovided with a s windings formed to effect at higher magnetic densities a magnetic leak by-passing said end-turn secondary windings.

14. A vacuum tube rectifier comprising: a pair of tubes each having a plate element and a filament element; primary windings; main secondary windings rovided with a neutral terminal interme iately thereof; end-turn secondary windings spaced from said primary and main secondary windings and having their inner terminals connected to the ends of said main secondary windings and their outer terminals connected one to one of said elements of one of said tubes and the other to one of said elements of the other of said tubes; and a core for said windings formed to eifect at higher magnetic densities a magnetic leak by-passing said end-turn secondary windings; said primary windings and said main secondary windings being an autotransformer. v

In testimony whereof I hereunto afiix my signature.

HARRY H. STRONG. 

